Heat-resistant optical moldings, and a process for their production
CA 2055772 A1 · Owner: Stehlin, Thomas · Inventors: Theis, Jurgen; Vaahs, Tilo; Bruck, Martin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Heat-resistant optical moldings, and a process for their production, A process for the production of optical moldings from polysilazanes or polyhydridochlorosilazanes in which the polysilazanes or polyhydridochlorosilazanes are pressed to give moldings or dissolved in a solvent and extruded and are subsequently exposed to a gas atmosphere at a temperature in the range from 10 to 200°C and a relative humidity in the range from 20 to 100% for from 0.1 to 24 hours. The moldings have a core/cladding structure the cladding, comprising from 1 to 3% by weight of O from 20 to 25% by, weight of N and from 30 to 40% by weight of Si and the, core comprising 100% by weight of a polysilazane or …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed November 18, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 18, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 18, 2013.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.